// bdlde_crc64.cpp                                                    -*-C++-*-
#include <bdlde_crc64.h>

///IMPLEMENTATION NOTES
///--------------------
// This implements the CRC-64 defined in ECMA 182 (with reversed polynomial
// 0xC96C5795D7870F42), in the usual manner:
//   http://en.wikipedia.org/wiki/Cyclic_redundancy_check

#include <bsl_ostream.h>
#include <bsls_annotation.h>
#include <bsls_types.h>

namespace BloombergLP {

// STATIC DATA

static const bsls::Types::Uint64 CRC_TABLE[256] = {
    0,
    0xb32e4cbe03a75f6fULL,
    0xf4843657a840a05bULL,
    0x47aa7ae9abe7ff34ULL,
    0x7bd0c384ff8f5e33ULL,
    0xc8fe8f3afc28015cULL,
    0x8f54f5d357cffe68ULL,
    0x3c7ab96d5468a107ULL,
    0xf7a18709ff1ebc66ULL,
    0x448fcbb7fcb9e309ULL,
    0x0325b15e575e1c3dULL,
    0xb00bfde054f94352ULL,
    0x8c71448d0091e255ULL,
    0x3f5f08330336bd3aULL,
    0x78f572daa8d1420eULL,
    0xcbdb3e64ab761d61ULL,
    0x7d9ba13851336649ULL,
    0xceb5ed8652943926ULL,
    0x891f976ff973c612ULL,
    0x3a31dbd1fad4997dULL,
    0x064b62bcaebc387aULL,
    0xb5652e02ad1b6715ULL,
    0xf2cf54eb06fc9821ULL,
    0x41e11855055bc74eULL,
    0x8a3a2631ae2dda2fULL,
    0x39146a8fad8a8540ULL,
    0x7ebe1066066d7a74ULL,
    0xcd905cd805ca251bULL,
    0xf1eae5b551a2841cULL,
    0x42c4a90b5205db73ULL,
    0x056ed3e2f9e22447ULL,
    0xb6409f5cfa457b28ULL,
    0xfb374270a266cc92ULL,
    0x48190ecea1c193fdULL,
    0x0fb374270a266cc9ULL,
    0xbc9d3899098133a6ULL,
    0x80e781f45de992a1ULL,
    0x33c9cd4a5e4ecdceULL,
    0x7463b7a3f5a932faULL,
    0xc74dfb1df60e6d95ULL,
    0x0c96c5795d7870f4ULL,
    0xbfb889c75edf2f9bULL,
    0xf812f32ef538d0afULL,
    0x4b3cbf90f69f8fc0ULL,
    0x774606fda2f72ec7ULL,
    0xc4684a43a15071a8ULL,
    0x83c230aa0ab78e9cULL,
    0x30ec7c140910d1f3ULL,
    0x86ace348f355aadbULL,
    0x3582aff6f0f2f5b4ULL,
    0x7228d51f5b150a80ULL,
    0xc10699a158b255efULL,
    0xfd7c20cc0cdaf4e8ULL,
    0x4e526c720f7dab87ULL,
    0x09f8169ba49a54b3ULL,
    0xbad65a25a73d0bdcULL,
    0x710d64410c4b16bdULL,
    0xc22328ff0fec49d2ULL,
    0x85895216a40bb6e6ULL,
    0x36a71ea8a7ace989ULL,
    0x0adda7c5f3c4488eULL,
    0xb9f3eb7bf06317e1ULL,
    0xfe5991925b84e8d5ULL,
    0x4d77dd2c5823b7baULL,
    0x64b62bcaebc387a1ULL,
    0xd7986774e864d8ceULL,
    0x90321d9d438327faULL,
    0x231c512340247895ULL,
    0x1f66e84e144cd992ULL,
    0xac48a4f017eb86fdULL,
    0xebe2de19bc0c79c9ULL,
    0x58cc92a7bfab26a6ULL,
    0x9317acc314dd3bc7ULL,
    0x2039e07d177a64a8ULL,
    0x67939a94bc9d9b9cULL,
    0xd4bdd62abf3ac4f3ULL,
    0xe8c76f47eb5265f4ULL,
    0x5be923f9e8f53a9bULL,
    0x1c4359104312c5afULL,
    0xaf6d15ae40b59ac0ULL,
    0x192d8af2baf0e1e8ULL,
    0xaa03c64cb957be87ULL,
    0xeda9bca512b041b3ULL,
    0x5e87f01b11171edcULL,
    0x62fd4976457fbfdbULL,
    0xd1d305c846d8e0b4ULL,
    0x96797f21ed3f1f80ULL,
    0x2557339fee9840efULL,
    0xee8c0dfb45ee5d8eULL,
    0x5da24145464902e1ULL,
    0x1a083bacedaefdd5ULL,
    0xa9267712ee09a2baULL,
    0x955cce7fba6103bdULL,
    0x267282c1b9c65cd2ULL,
    0x61d8f8281221a3e6ULL,
    0xd2f6b4961186fc89ULL,
    0x9f8169ba49a54b33ULL,
    0x2caf25044a02145cULL,
    0x6b055fede1e5eb68ULL,
    0xd82b1353e242b407ULL,
    0xe451aa3eb62a1500ULL,
    0x577fe680b58d4a6fULL,
    0x10d59c691e6ab55bULL,
    0xa3fbd0d71dcdea34ULL,
    0x6820eeb3b6bbf755ULL,
    0xdb0ea20db51ca83aULL,
    0x9ca4d8e41efb570eULL,
    0x2f8a945a1d5c0861ULL,
    0x13f02d374934a966ULL,
    0xa0de61894a93f609ULL,
    0xe7741b60e174093dULL,
    0x545a57dee2d35652ULL,
    0xe21ac88218962d7aULL,
    0x5134843c1b317215ULL,
    0x169efed5b0d68d21ULL,
    0xa5b0b26bb371d24eULL,
    0x99ca0b06e7197349ULL,
    0x2ae447b8e4be2c26ULL,
    0x6d4e3d514f59d312ULL,
    0xde6071ef4cfe8c7dULL,
    0x15bb4f8be788911cULL,
    0xa6950335e42fce73ULL,
    0xe13f79dc4fc83147ULL,
    0x521135624c6f6e28ULL,
    0x6e6b8c0f1807cf2fULL,
    0xdd45c0b11ba09040ULL,
    0x9aefba58b0476f74ULL,
    0x29c1f6e6b3e0301bULL,
    0xc96c5795d7870f42ULL,
    0x7a421b2bd420502dULL,
    0x3de861c27fc7af19ULL,
    0x8ec62d7c7c60f076ULL,
    0xb2bc941128085171ULL,
    0x0192d8af2baf0e1eULL,
    0x4638a2468048f12aULL,
    0xf516eef883efae45ULL,
    0x3ecdd09c2899b324ULL,
    0x8de39c222b3eec4bULL,
    0xca49e6cb80d9137fULL,
    0x7967aa75837e4c10ULL,
    0x451d1318d716ed17ULL,
    0xf6335fa6d4b1b278ULL,
    0xb199254f7f564d4cULL,
    0x02b769f17cf11223ULL,
    0xb4f7f6ad86b4690bULL,
    0x07d9ba1385133664ULL,
    0x4073c0fa2ef4c950ULL,
    0xf35d8c442d53963fULL,
    0xcf273529793b3738ULL,
    0x7c0979977a9c6857ULL,
    0x3ba3037ed17b9763ULL,
    0x888d4fc0d2dcc80cULL,
    0x435671a479aad56dULL,
    0xf0783d1a7a0d8a02ULL,
    0xb7d247f3d1ea7536ULL,
    0x04fc0b4dd24d2a59ULL,
    0x3886b22086258b5eULL,
    0x8ba8fe9e8582d431ULL,
    0xcc0284772e652b05ULL,
    0x7f2cc8c92dc2746aULL,
    0x325b15e575e1c3d0ULL,
    0x8175595b76469cbfULL,
    0xc6df23b2dda1638bULL,
    0x75f16f0cde063ce4ULL,
    0x498bd6618a6e9de3ULL,
    0xfaa59adf89c9c28cULL,
    0xbd0fe036222e3db8ULL,
    0x0e21ac88218962d7ULL,
    0xc5fa92ec8aff7fb6ULL,
    0x76d4de52895820d9ULL,
    0x317ea4bb22bfdfedULL,
    0x8250e80521188082ULL,
    0xbe2a516875702185ULL,
    0x0d041dd676d77eeaULL,
    0x4aae673fdd3081deULL,
    0xf9802b81de97deb1ULL,
    0x4fc0b4dd24d2a599ULL,
    0xfceef8632775faf6ULL,
    0xbb44828a8c9205c2ULL,
    0x086ace348f355aadULL,
    0x34107759db5dfbaaULL,
    0x873e3be7d8faa4c5ULL,
    0xc094410e731d5bf1ULL,
    0x73ba0db070ba049eULL,
    0xb86133d4dbcc19ffULL,
    0x0b4f7f6ad86b4690ULL,
    0x4ce50583738cb9a4ULL,
    0xffcb493d702be6cbULL,
    0xc3b1f050244347ccULL,
    0x709fbcee27e418a3ULL,
    0x3735c6078c03e797ULL,
    0x841b8ab98fa4b8f8ULL,
    0xadda7c5f3c4488e3ULL,
    0x1ef430e13fe3d78cULL,
    0x595e4a08940428b8ULL,
    0xea7006b697a377d7ULL,
    0xd60abfdbc3cbd6d0ULL,
    0x6524f365c06c89bfULL,
    0x228e898c6b8b768bULL,
    0x91a0c532682c29e4ULL,
    0x5a7bfb56c35a3485ULL,
    0xe955b7e8c0fd6beaULL,
    0xaeffcd016b1a94deULL,
    0x1dd181bf68bdcbb1ULL,
    0x21ab38d23cd56ab6ULL,
    0x9285746c3f7235d9ULL,
    0xd52f0e859495caedULL,
    0x6601423b97329582ULL,
    0xd041dd676d77eeaaULL,
    0x636f91d96ed0b1c5ULL,
    0x24c5eb30c5374ef1ULL,
    0x97eba78ec690119eULL,
    0xab911ee392f8b099ULL,
    0x18bf525d915feff6ULL,
    0x5f1528b43ab810c2ULL,
    0xec3b640a391f4fadULL,
    0x27e05a6e926952ccULL,
    0x94ce16d091ce0da3ULL,
    0xd3646c393a29f297ULL,
    0x604a2087398eadf8ULL,
    0x5c3099ea6de60cffULL,
    0xef1ed5546e415390ULL,
    0xa8b4afbdc5a6aca4ULL,
    0x1b9ae303c601f3cbULL,
    0x56ed3e2f9e224471ULL,
    0xe5c372919d851b1eULL,
    0xa26908783662e42aULL,
    0x114744c635c5bb45ULL,
    0x2d3dfdab61ad1a42ULL,
    0x9e13b115620a452dULL,
    0xd9b9cbfcc9edba19ULL,
    0x6a978742ca4ae576ULL,
    0xa14cb926613cf817ULL,
    0x1262f598629ba778ULL,
    0x55c88f71c97c584cULL,
    0xe6e6c3cfcadb0723ULL,
    0xda9c7aa29eb3a624ULL,
    0x69b2361c9d14f94bULL,
    0x2e184cf536f3067fULL,
    0x9d36004b35545910ULL,
    0x2b769f17cf112238ULL,
    0x9858d3a9ccb67d57ULL,
    0xdff2a94067518263ULL,
    0x6cdce5fe64f6dd0cULL,
    0x50a65c93309e7c0bULL,
    0xe388102d33392364ULL,
    0xa4226ac498dedc50ULL,
    0x170c267a9b79833fULL,
    0xdcd7181e300f9e5eULL,
    0x6ff954a033a8c131ULL,
    0x28532e49984f3e05ULL,
    0x9b7d62f79be8616aULL,
    0xa707db9acf80c06dULL,
    0x14299724cc279f02ULL,
    0x5383edcd67c06036ULL,
    0xe0ada17364673f59ULL
};

namespace bdlde {
                                // -----------
                                // class Crc64
                                // -----------

// MANIPULATORS
void Crc64::update(const void *data, bsl::size_t length)
{
    BSLS_ASSERT(data || !length);

    const unsigned char *d = (const unsigned char *)data;
    bsls::Types::Uint64 tmp = d_crc;

    switch (length % 8) {
      case 7:
        tmp = CRC_TABLE[(tmp ^ *d++) & 0xff] ^ (tmp >> 8);
        BSLS_ANNOTATION_FALLTHROUGH;
      case 6:
        tmp = CRC_TABLE[(tmp ^ *d++) & 0xff] ^ (tmp >> 8);
        BSLS_ANNOTATION_FALLTHROUGH;
      case 5:
        tmp = CRC_TABLE[(tmp ^ *d++) & 0xff] ^ (tmp >> 8);
        BSLS_ANNOTATION_FALLTHROUGH;
      case 4:
        tmp = CRC_TABLE[(tmp ^ *d++) & 0xff] ^ (tmp >> 8);
        BSLS_ANNOTATION_FALLTHROUGH;
      case 3:
        tmp = CRC_TABLE[(tmp ^ *d++) & 0xff] ^ (tmp >> 8);
        BSLS_ANNOTATION_FALLTHROUGH;
      case 2:
        tmp = CRC_TABLE[(tmp ^ *d++) & 0xff] ^ (tmp >> 8);
        BSLS_ANNOTATION_FALLTHROUGH;
      case 1:
        tmp = CRC_TABLE[(tmp ^ *d++) & 0xff] ^ (tmp >> 8);
        BSLS_ANNOTATION_FALLTHROUGH;
      case 0: ;
    }

    bsl::size_t n = length / 8;
    while (n) {
        tmp = CRC_TABLE[(tmp ^ *d++) & 0xff] ^ (tmp >> 8);
        tmp = CRC_TABLE[(tmp ^ *d++) & 0xff] ^ (tmp >> 8);
        tmp = CRC_TABLE[(tmp ^ *d++) & 0xff] ^ (tmp >> 8);
        tmp = CRC_TABLE[(tmp ^ *d++) & 0xff] ^ (tmp >> 8);
        tmp = CRC_TABLE[(tmp ^ *d++) & 0xff] ^ (tmp >> 8);
        tmp = CRC_TABLE[(tmp ^ *d++) & 0xff] ^ (tmp >> 8);
        tmp = CRC_TABLE[(tmp ^ *d++) & 0xff] ^ (tmp >> 8);
        tmp = CRC_TABLE[(tmp ^ *d++) & 0xff] ^ (tmp >> 8);
        --n;
    }

    d_crc = tmp;
}

// ACCESSORS
bsl::ostream& Crc64::print(bsl::ostream& stream) const
{
    static const char hex[] = "0123456789abcdef";
    bsls::Types::Uint64 crc = checksum();

    char out[] = "0x0123456789abcdef";  // room for 16 digits plus "0x" and NUL
    for (int i = 0; i < 8; ++i) {
        unsigned char byte = (crc >> (56 - (i * 8))) & 0xff;
        out[2 + 2 * i] = hex[byte >> 4];
        out[3 + 2 * i] = hex[byte & 0xf];
    }
    return stream << out;
}

}  // close package namespace
}  // close enterprise namespace

// ----------------------------------------------------------------------------
// Copyright 2017 Bloomberg Finance L.P.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ----------------------------- END-OF-FILE ----------------------------------
